Radiocarbon Measurements of Samples Collected from Conglomeratic Beachrock Developing at Higashihama-cho, Sasebo, Nagasaki Prefecture

DOI Web Site 1 Citations 4 References
  • OMOTO Kunio
    Graduate School of Science and Technology, Nihon University and College of Humanities and Sciences, Nihon University, retired
  • IKEDA Akiko
    Technical Center of Nagoya University
  • YOKOO Yoriko
    Faculty of Science and Engineering, Doshisha University

Bibliographic Information

Other Title
  • 長崎県佐世保市東浜町の礫岩質ビーチロックから採取した試料の放射性炭素年代測定

Abstract

<p> A total of four muddy–fine sand deposits attached to the undersides of cobles and boulders and three Claudiconcha japonica fossils were collected to determine the formation age of conglomeratic beachrock developing at Sasebo, Nagasaki prefecture. The geology of the surveyed coast consists of non-limestone rocks. Radiocarbon dating using Accelerator Mass Spectrometry (AMS14C dating) for the collected samples was conducted to determine the formation age of the beachrock. It was not possible to determine the age of four muddy–fine sand deposits because of their low CaCO3 concentrations (1.4%); however, the Claudiconcha japonica fossils yielded an age of Modern (102.5 ± 0.3 pMC–101.6 ± 0.3 pMC). The elemental composition of the cement samples analyzed with ICP-MS showed Al and Fe concentrations of 6.9% and 4.9%, respectively; however, the Ca concentration was low at 0.6%. The analytical results lead to the conclusion that the formation age of conglomeratic beachrock at Sasebo could not be determined with AMS14C dating, and that cobles and boulders, including mud and fine sand deposits, were cemented with Al2O3 and Fe2O3, or probably with SiO2, and formed conglomeratic beachrock.</p>

Journal

Citations (1)*help

See more

References(4)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top